OBD Guide

U0304

Software Incompatibility With Gear Shift Control Module A

U0304 is an OBD-II diagnostic trouble code meaning: Software Incompatibility With Gear Shift Control Module A. Common causes: incompatible software versions in the ecu and gearshift module, software update error. Estimated repair cost: ~$167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
~$167 (est.)

Symptoms

  • Incorrect gear shifting
  • Check Engine Light Illuminates
  • Loss of engine power
  • Switching to emergency mode
  • Problems starting the engine

Causes

  • Incompatible software versions in the ECU and gearshift module
  • Software update error
  • Damage to module software
  • Shift module malfunction
  • Problems with communication between modules

How to Fix

  1. Check software versions in both modules
  2. Update or reinstall the software in the problematic module
  3. Check the integrity of the wiring harness between the modules
  4. Test the gear shift module
  5. If necessary, replace the gear shift module

Related codes

Error U0304 by Vehicle Brand

FAQ

What does the U0304 code mean?

U0304 is an OBD-II diagnostic trouble code that indicates: Software Incompatibility With Gear Shift Control Module A

What causes a U0304 error code?

The most common causes of U0304 include: Incompatible software versions in the ECU and gearshift module; Software update error; Damage to module software; Shift module malfunction.

How do I fix a U0304 diagnostic trouble code?

To fix U0304: Check software versions in both modules. Update or reinstall the software in the problematic module. Check the integrity of the wiring harness between the modules. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U0304?

Limited driving only, diagnose soon

How much does it cost to fix U0304?

The estimated repair cost for U0304 is ~$167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat